1. Field of the Invention
The present invention provides a system for delivery an additive to a flowing fluid. More particularly, the invention relates to a system for delivering an additive to a flowing fluid wherein the system is in whole or in part powered by the flow of the fluid.
2. Description of the Related Art
Systems for introducing measured fluids into flowing fluids are well known. A popular means of injecting chemical additives into various liquid streams, particularly fuels, is to use a signal generated from a flow meter in the recipient line to control an injection pump. Various systems exist to meter the amount of additive(s) injected into a fluid, usually drawing electrical power from the system associated with the fluid delivery. These systems generally inject the fluid additive into the flow of the main fluid, causing the fluid additive to stratify and not blend thoroughly, often precluding the desired outcome or requiring excessive amounts of fluid additive to obtain the desired benefit. Some additives such as lubricity agents and conductivity agents that are injected at a very low rate (PPM) can be ineffective if not blended thoroughly.
Moreover, each additive requires its own reservoir and generally its own pump, particularly where multiple additives may be simultaneously added.
Current systems suffer from a number of shortcomings. Most systems are not self-contained, requiring substantial effort to address any issues within the system or to make changes. Additionally, some systems use error-correcting control systems which, based on data reported to a computer from product and additive meters, open or close a valve attached to a highly pressurized additive supply line (such as 165 psi) until the desired volume of additive has been delivered for the product, according to volume of product reported by the main product meter. As a result of the error correction system employed, these systems typically provide an oversupply of additive to ensure minimum delivery, an undesirable and costly approach, as are constantly in a state of correction in search of the calculated ratio.
Among the systems known in the art which have attempted to address some of these shortcomings are U.S. Pat. No. 5,513,963 issued to Walton for a direct action fluid motor and injection pump, U.S. Pat. No. 6,910,405 issued to Walton, et. al. for an on/off switch for a liquid additive injection pump, and U.S. Pat. No. 7,066,353 issued to Hammonds for a fluid powered additive injection system. However, none of these systems have provided a self-contained system incorporating a fluid motor, speed sensor, electricity generator and battery, a clutch operated additive control pump, a flow meter and a computer controller, particularly one capable of relatively-low pressure operation.